What a Diesel Pusher Taught Us About Hidden Leaks

Where the Water Was Getting In

The finding that started it all on this 2025 Entegra Cornerstone Class A diesel pusher was water. The customer had documented, on video, moisture entering the cabin along the top of the streetside front window. That is the kind of thing that keeps RV owners up at night, and rightly so. Water is patient, and it rarely announces where it actually started.

When we traced it back, we found a documented separation between the front cap and the sidewall, right up near the gutter spout. That seam is a common trouble spot on a coach this size, and once it opens up even a little, water has an easy path to follow down and behind the window frame.

This is exactly why we do not stop at the first thing we see. A window that is letting water in in the cabin is a symptom, not the whole story, and the real question is how far back the water has traveled and what it has touched along the way. That means looking at the cap seam itself, checking the window frame and the wall behind it for signs of moisture, and documenting all of it so there is a clear picture of what is actually going on before anyone talks about fixing anything.

Following the Trail Up to the Roof

Up on the roof, the curbside front raceway mounting hardware had an Eternabond tape patch that someone had applied at some point. It was starting to peel and separate from the surface.

Eternabond is good tape, but a patch that is lifting tells us something important: whatever is underneath it was a problem before, and it is worth a much closer look now. A peeling patch can trap and channel water while looking like it is doing its job, which makes it easy to miss if you are not specifically checking for it. We flagged this for further diagnostics. The tape, the mounting hardware, and the roof sealant underneath all need a proper look before anyone can say what is really going on there.

While we were up there, we found one more thing worth watching. The rear A/C unit was draining onto the roof and pooling on the streetside. We could see water coming out of the rear drain line but could not definitively pin down every source of it. That points us toward the condensate drain lines and the connections inside the A/C unit itself as places that need a closer look by a qualified RV technician, since pooling water on a roof is never something you want to shrug off.

Why Documented, Professional Work Catches This

A separation up by the gutter spout, a peeling tape patch behind a roof raceway, condensate pooling on the streetside: none of these are things most owners would ever spot on their own. They live in the places you do not walk, on top of a coach you do not climb, hidden behind a window frame that looks perfectly fine from the inside until it does not.

That is the value of getting up there, looking carefully, and writing down exactly what we see. When we tell you a source of water needs further diagnostics before anyone guesses at a fix, that is us doing the job the right way. As NRVIA Certified Inspector standards call for, we would rather flag something for further evaluation than assume we already know the answer. Here in NW Arkansas we get plenty of hard rain and swinging humidity, and a coach that is not sealed up tight will find that out the hard way.

Documented findings also give you a real record. You know what was found, what still needs a closer look, and what to keep an eye on down the road.

Think there might be water sneaking in where you cannot see it? Schedule service and let us track it down before it becomes a much bigger repair.